Supporting and weighing device



April 20, 1965 H. w. LINK 3,179,192

SUPPORTING AND WEIGHING' DEVICE Filed April l, 1963 INVENTOR. /yfey'Zer)f1/77%.

United States Patent O 3,179,192 SUPPRTING AND WEIGHING DEVICE HerbertW. Link, 8330 Sorrento, Detroit, Mich. Filed Apr. 1, 1963, Ser. No.269,376 Claims. (Cl. 177-208) This invention relates to a supporting andweighing device, and more particularly to improvements in devices ofthis type.

The present invention relates more especially to improvements in thetype of device shown in the patent to Weber Number 2,956,761, datedOctober 18, 1960.

Devices of this type comprise a platform upon which the load issupported and lluid pressure means for supporting the platform, the Huidpressure being controlled by a pilot valve actuated by changes in theload, to maintain the platform at a constant level.

In devices of this type the platform moves vertically with respect toits supporting structure in response to changes in the load, and in useis apt to become tilted or canted and bind on its support and thusdeleteriously aifect its operation of the pilot valve.

lt is therefore a primary object of this invention to provide a deviceof this type having improved means for transmitting the movement of theplatform to the pilot valve so that any tilting or canting of theplatform will not affect the operation of the pilot valve.

Another object is to provide a device of this type in which theconnection between the platform and the pilot valve actuating mechanismcomprises a point Contact whereby if the platform tilts it will rockabout this point contact and not disalign the remainder of the pilotvalve actuating mechanism.

The' objects and advantages of this invention are accomplished by "asimple but eective mechanism which comprises a supporting or guide rodor extension on the platform depending perpendicularly therefrom andhaving a point contact with a vertically movable plunger, laterallysupported by a bearing member, such as a series of ball bearings. Theplunger engages one end of an arm or lever pivotally supportedintermediate its length for rocking movement. The other end of the armor lever activates the pilot valve. Thus any tilting movement of theplatform takes place about the point contact and will not affect theoperation of the rest of the pilot valve actuating mechanism.

The various objects and advantages, and the novel details ofconstruction of one commercially practical embodiment of the inventionwill become more apparent as this description proceeds, especially whenconsidered in connection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal verticle sectional view through a supportingand weighing device constructed in accordance with the invention;

FIGURE 2 is a fragmentary sectional view taken substantially on theplane indicated by line 2-2 in FIG- URE l, this view being on a smallerscale and partly in elevation; and

FIGURE 3 is a detail sectional view taken substantially on the planeindicated by line 3 3 in FIGURE 2.

The device of this invention consists essentially of a base plate 10, aload supporting platform 11, a reservoir 12, a center support 13 for theload supporting platform, a pilot valve 14 for controlling the supply ofair tov the reservoir 12 and a rockable arm or lever 15 for transmittingthe vertical movement of the platform to a movable part of the pilotValve 14. j

The load supporting platform 11 consists of a top plate Ztl providedwith an annular depending ange 21 which defines the outer wall of an airchamber 22.

The inner wall of the air chamber 22 is formed by a lCC wall 23 of thereservoir which is in the form of an inverted substantiallydoughnut-shaped member. The outer edge of the wall 23 of the reservoir12 engages an annular upwardly extending wall 24 formed on the baseplate 10 and the inner wall of the reservoir engages an upwardlyextending central sleeve-like portion or wall 25 extending upwardly fromthe base 10. The outer and inner edges of the wall 23 of the reservoirare sealed to the elements 24 and 25.

As described in theV aforesaid patent, restricted communication isestablished between lthe reservoir 12 and the chamber 22 by means of arestricted opening 26 formed in the wall of the reservoir.

The space between the wall 23 of the reservoir and the annular llange 21of the load supporting platform is sealed at the lower end thereof bymeans of a hollow tubular sealing ring 30 formed of a suitable plasticor other elastomeric material. The space between the inner wall 23a ofthe reservoir and a centrally arranged depending extension 31 on theload supporting platform 11 is also sealed by a hollow tubular sealingring 32. The normal diameter of the sealing rings 30 and 32 is greaterthan the distance between the adjacent walls which they engage so thatthese annular rings are substantially flattened when inserted.Therefore, as the load supporting platform moves up and down, thesealing rings 30 and 32 roll along the opposed surfaces to effectivelyseal the space between the reservoir and the load supporting platform.

The centrally arranged extension 31 is in the form of a supporting studor rod and is rigidly connected to the load supporting platform andextends perpendicularly therefrom in a downward direction. The end ofthis rod or extension 31 is provided with a semispherical element orrounded button-like member 35 so as to provide a point Contact with averticallyrnovable plunger, yet to be described. Thus, irrespective ofany tilting movement of the load supporting platform 11, this movementwill not be transmitted to the plunger and will not cause a binding ofthe parts which operate the pilot valve 14.

Arranged within the sleeve-like portion or wall 25 is a bearing sleeve36, and located within the bearing sleeve is a bearing cage 37 havingspaced sets of ball bearings 38 arranged in two rows each with the ballsof one row being circumferentially staggered with respect to the ballsof the adjacent row. Arranged within the bearing gauge is a plunger 39.lt will be noted that with the ball bearings arranged in sets spacedlongitudinally of the plunger 39, these bearings provide lateral supportfor the plunger while permitting frictionless longitudinal movementthereof.

The upper end of the plunger 39 is in engagement with the semisphericalmember 35 and, as stated, has a point contact therewith which will notbe affected by any tilting movement of the load supporting platform 11.The lower end of the plunger 39 engages one end 40 of the rockable armor lever 15. The other end of the lever is provided with an adjustablestud 41 adapted to engage and actuate a movable part of the pilot valve14, yet to be described.

The rockable arm or lever 15 is pivoted intermediate its length on aknife edge bearing i2 which engages a V- shaped recess 43 formed in theunderside of the rockable lever 15. The rockable lever 15 operates in acutaway portion 44 formed in the base plate 10. The knife edge bearingmember 42, see FIGURES 2 and 3, is provided with laterally extendingears or lugs 45 and the bearing member 42 with its lugs 45 is insertedin a cutaway portion 46 formed transversely of the base plate lt) and issecured to the base plate by means of fastening elements 47; seeparticularly FIGURES 2 and 3.

The load supporting platform 11 is guided in its vertical movement bymeans of laterally extending lugs 50, each provided with an aperture 51which engages an adjustable member 52 secured to the baseA plate llt);see the left-hand side of FGURE l.

The pilot valve shown at the right-hand side of FIG- URE l issubstantially the same in its operation as the pilot valve shown anddescribed in the aforesaid patent. It consists of a housing 6i? providedwith a valve stem 6l having a valve part 62 adapted to normally close aport 63 interposed in an air inlet 64. The valve also comprises aplunger 65 (heretofore referred to as the movable part of the pilotvalve) provided with an exhaust passage 66. Air is permitted to exhaustfrom the interior of the housing eti through an exhaust passage 6'7extending through a screw 68 arranged in a removable plug 69 in the sidewall of the housing.

The plunger d is connected to a diaphragm 7) which extends across thevalve housing d@ to define a chamber 7l. This chamber is connected byports or passages 72 and 73 to the reservoir l2. The exhaust passage dois normally closed by the end 74 :of the valve stem 6l. A spring 7Snormally urges the valve stem 6l to closed position. The adjustable stud41 on the rockable lever f5 engages the end of the plunger 65 to actuatethe latter.

When the load on the load supporting platform increases, the rod orextension 31 will move the plunger 39 downwardly and rock the rockablelever so that the stud 4l thereon will raise the plunger 65 and thusopen the inlet port 63 to permit an additional supply of air underpressure to flow through the chamber 71, and through ports '72 and 73into the reservoir to counteract the increase in the load. When,however, the load is lightened and the load supporting platform risesabove its normal level, the air in the chamber 71 will, through thediaphragm 70, lower the plunger d5 and open the exhaust port 66 topermit air to escape from the reservoir so that the load supportingplatform will return to its normal position.

The pressure of air in the system may be measured by a gauging device 8)connected by a conduit Sl to the passageway 72. The dial of the gauge ispreferably calibrated to indicate in pounds the load placed upon theload supporting platform.

No claim is made herein to the pilot valve l@ or to the measuring device30, as they form no part of this invention.

In will be understood from the foregoing that if the load supportingplatform lll is tilted or canted, during operation of the device, due tothe fact that the load is not placed squarely on the center of theplatform, it will make no difference because the load supportingplatform will rock about the semispherical element 35 and thus maintaina line contact with the plunger 39. Thus, the plunger 39 and therockable lever 15 will not be deleteriously affected by any tiltingmovement of the platform whereby the movable valve part is alwaysproperly actuated in response to any movement of the platform. Thus, thestructure described heretofore provides a simple but effective means foraccurately actuating the pilot valve under all conditions of operation.

While a commercially practical embodiment of the invention has beendescribed and illustrated herein somewhat in detail, it will beunderstood that various changes may be made as may come within thepurview of the accompanying claims.

What is claimed is:

l. In a device of the class described, a vertically movable loadsupporting platform, a centrally arranged extension on said platform, avertically guided plunger, means providing a point contact between saidextension and plunger, a pilot valve having a movable part, and an armpivotally supported intermediate its length for rocking movementengaging said plunger and the movable part of the pilot valve fortransmitting the verticle movement of said platform to said movablevalve part.

2. In a device of the class described, a vertically movable loadsupporting platform having a centrally arranged lil supporting roddepending therefrom, a vertically guided plunger, rounded means forminga point contact between said supporting rod and plunger, a pilot valvehaving a movable part, and a roclrable arm pivotally supportedintermediate its length for transmitting the movement of said plunger tosaid movable valve part.

3. n a device of the class described, a vertically movable loadsupporting platform having a centrally arranged supporting rod dependingtherefrom, a plunger', antifriction bearing for mounting said plungerfor vertical movement, means providing a point contact between theadjacent ends of said supporting rod and plunger, a pilot valve having amovable part, and a roclcably supported arm having one end engaging saidplunger and the other end engaging said movable valve part fortransmitting the vertical movement of said platform to said movablevalve part.

4. ln a supporting and weighing device comprising, a base plate, areservoir secured to said base plate, a vertically movable loadsupporting platform havinsT a portion arranged in spaced telescopicrelation with said reservoir and forming a chamber therebetween, and apilot valve having a movable part for controlling air pressure in saidchamber, that improvement which comprises, a centrally arrangeddepending extension on said platform, a plunger having antifrictionbearing for mounting said plunger for vertical movement, means providinga point Contact between the adjacent ends of said extension and plunger,and a rockable arm pivotally supported intermediate its length andhaving its ends engaging respectively said plunger and movable Valvepart for transmitting the vertical movement of said platform to saidmovable valve part.

5. A device as described in claim 4 in which the means providing thepoint contact consists of a semispherical element carried by the end ofsaid extension.

6. In a supporting and weighing device comprising, a base plate, areservoir secured to said base plate, a vertically movable loadsupporting platform having a portion arranged in spaced telescopicrelation with said reservoir and forming a chamber therebetween, and apilot valve having a movable part for controlling air pressure in saidchamber, that improvement which comprises, a supporting rod rigidlysecured to said platform and extending perpendicularly therefrom in adownward direction, a plunger, means for mounting said plunger forvertical movement comprising a bearing sleeve carried by said reservoirin spaced relation to said plunger and a cylindrical bearing cage in thespace between said plunger and bearing sleeve having sets of bearingelements located adjacent the ends thereof, and a rockable arm pivotallysupported intermediate its length and having its ends engagingrespectively said plunger and movable valve part for transmitting thevertical movement of said platform to said movable valve part.

7. A device as described in claim 4 in which the end of the rockable armengaging the movable valve part is provided with an adjustable stud.

8. A device as described in claim 4 in which the pivotal support for therockable arm consists of a knife edge bearing engaging a V-shaped recessin the roclrable arm.

9. In a device of a class described, a base, a vertical movableload-supporting platform, means for sealing said platform to said baseto form an air chamber, valve means 0n said base, means in said valvemeans for controlling the iiow of fluid to and from said air chamber,and a roclcable lever connected to said valve and to said platform in amanner to have the movement of the platform transferred to said valve tocontrol the pressure in the chamber relative to the change in load onthe platform which produced its movement.

l0. In a device of a class described, a base, a vertical movableload-supporting platform, means for sealing said platform to said baseto form an air chamber, valve means on said base, means in said valvemeans for controlling the flow of fluid to and from said air chamber,and a 5 rockable lever connected to said valve and to said platform in amanner to have the movement of the platform transferred to said valve tocontrol the pressure in the chamber relative to the change in load onthe platform which produced its movement, said lever` engaging thecenter of 5 said platform and said valve means.

References Cited by the Examiner UNITED STATES PATENTS 1/46 Saunders177-208 10/60 Weber 177-208 X 10/ 61 Blazek et al. 308-6 12/63 Weber177-209 FOREIGN PATENTS 4/ 35 Germany.

ROBERT L. EVANS, Primary Examiner.

3/3'1 Frisch 177-208 10 LEO sMrLow, Examiner.

1. IN A DEVICE OF THE CLASS DESCRIBED, A VERTICALLY MOVABLE LOADSUPPORTING PLATFORM, A CENTRALLY ARRANGED EXTENSION ON SAID PLATFORM, AVERTICALLY GUIDED PLUNGER, MENS PROVIDING A POINT CONTACT BETWEEN SAIDEXTENSION AND PLUNGER, A PILOT VALVE HAVING A MOVABLE PART, AND AN ARMPIVOTALLY SUPPORTED INTERMEDIATE ITS LENGTH FOR ROCKING MOVEMENTENGAGING SAID PLUNGER AND THE MOVABLE PART OF THE PILOT VALVE FORTRANSMITTING THE VERTICLE MOVEMENT OF SAID PLATFORM TO SAID MOVABLEVALVE PART.